The field of the invention is coatings for orthopedic implant materials.
Orthopedic implants are commonly coated with bioactive ceramics, particularly calcium phosphate (a naturally-occurring bone mineral), to provide a surface suitable for the ingrowth of bone tissue. The ingrowth of bone tissue results in secure fixation of the implant to existing bone. It is known in the art that coatings may be applied to an implant by slip casting, plasma spraying, and electrophoretic deposition.
Ducheyne et al. (U.S. Pat. No. 4,990,163) disclose the use of powdered calcium phosphate compounds dissolved in isopropanol for electrophoretic deposition of a bioactive coating on implant surfaces. The coating is said to have a high dissolution rate.
Phillips et al. (U.S. Pat. No. 3,892,648) disclose the electrophoretic deposition of bone particles in a collagen-bearing medium on orthopedic implants. Collagen fibrils are dispersed in a gelatin medium; the resulting gelled collagen is next dispersed in a water/glycerine solution, and finely divided bone is added to the solution. The solution is used in an electrophoretic deposition process to create a coating of bone and collagen on an implant surface.